5 Tips for Winterizing Your Terracotta Pottery

To many people winterizing terra cotta pottery may seem like a completely irrelevant subject for discourse, but consider that you can add this information to your knowledge just IN CASE it ever gets cold enough to freeze. This is an actual problem for people with terracotta pots in parts of the US , which is why you don’t see great pottery everywhere.

There ARE steps that can be taken to help prevent your pots from cracking when old man winter whips through your garden. The goal is to eliminate the possibility of water being absorbed, frozen and thus causing the pot to crack.

1. Lift the pot from the ground by placing it on pot feet, wooden blocks or pieces of stone. This will allow air to circulate beneath the pot.
2. Seal the pot with a penetrating sealer, such as one used to seal slate floors and swimming pools
3. Remove plants and soil from the pot, as the soil will absorb water, freeze, expand and can cause cracking
4. Cover the pot with plastic sheeting to avoid contact with water
5. Most fool-proof: move it inside

Much depends on the quality of the terra cotta as well.  Eye of the Day’s is the highest quality, high fired Italian terracotta, made from Galestro clay. Our pots, manufactured by Terrecotte San Rocco, are guaranteed frost proof to minus 15 degrees. It helps to know that if a pot is high-fired, the absorption rate is lower, and so the risk of cracking in freezing weather is reduced.

You may need this information some day. Maybe.

Photo Credit: Terracotta Pots, Creative Commons, My Container Garden After Winter by Rachel James is licensed under CC BY-NC-ND 2.0

How It Works: Frostproof Terracotta

It’s hard to believe that it is already Fall. In California, leaves don’t change much in a drought, no matter what time of year. But as another October becomes a thing of the past, much of the country can already feel the promise of winter. So let’s talk about frostproof terracotta.

Many of you live and work in places that freeze, and much has been said, both by homeowners and garden designers about the freeze/thaw capability of ceramic plant containers. Remember that ‘clay’ is the earthen material, ‘ceramic’ is the clay when it has been fired. Terracotta is low fire red clay found all over the world. There are low fire clay bodies, and high fire clay bodies. Low fire is also referred to as earthenware, high fire is stoneware. Once clay is fired it becomes ceramic no matter what temperature it is fired to. But that doesn’t mean it is mature. I want to introduce you to two new key words: “vitrify” and “absorption.”

Every clay, whether earthenware or stoneware, has an optimum maturation point when fired. When this point is reached, the clay is “vitrified.” When clay becomes vitreous, it means that all the different ingredients in the clay have melted and bonded together to form a mature, very strong, “ceramic.” If a clay is over-fired it becomes flakey and worthless. If a clay is under-fired (like many of the pottery containers that are called “terracotta”) it is weak and porous and highly susceptible to cracking, even without being frozen. So when we talk about frostproof ceramic or terracotta, interestingly enough, we have to talk about fire first. In ceramics it always, always, always, comes back to the fire.

The key equation: the more vitrified, the less absorption. Did you catch that? Absorption yields expansion/contraction and hence cracking, during a freeze/thaw cycle. That’s basically it. You’ve got clay, you’ve got fire, you’ve got maturation/vitrification, and you’ve got frostproof ceramic. Or, more plainly put, if a ceramic vessel is not fired to its target temperature, it will die an easy death no matter what the weather is doing.  But if it will last longer than you do.  Just think about that for a moment.

Here is what you can do when you are ready to purchase frostproof ceramic containers:

1) Research the manufacturer’s credibility. If you are buying real, frostproof ware, know where it comes from and how it was fired, and get something on paper, like a warranty.

2) Protect your investment! Do not add moisture to a vessel that you know is going to freeze. And if you are going to take the time to cover the plants, take the time to cover the container too. Start to think of the ceramics as a living, breathing, expanding and contracting entity, just like the plant that it holds.

3) IMMEDIATELY call Eye of the Day. They have been selling frostproof terracotta for more than fifteen are not only knowledgeable, but relatively good looking and congenial, and carry the best frostproof terracotta on the market (guaranteed to withstand temperatures down to minus 15° F).

4) Move to California!

Holiday time is approaching, but that doesn’t mean there isn’t time to get a little gardening in between the shopping and entertaining. Since the sun is shining less brightly, the soil has started to cool. Lower light and shorter days mean less productivity for plants.

Here are some ideas for winter gardening:

1. Plant for the Coming Cool Season

Winter vegetables include everything in the cabbage family: broccoli, cauliflower, mustard greens, and everyone’s new favorite—kale. Any of these can be grown as row crops for the kitchen, but consider putting a few in a half barrel or other container for both their edible and ornamental uses. Colorful rainbow chard is another great choice.

2. Consider Color

Cool season flowers like bachelor’s button, stock, sweet alyssum, calendula, foxglove, Iceland poppies, and pansies all thrive as winter approaches. Pick a color palette of similar or contrasting tones and group different types together in the container of your choice. Only one or two colorful pots will lend a festive air to your patio or deck. If you tuck in a few dormant bulbs, they will take over as the annuals wane. Narcissus and all its forms, gladiolus, lilies, tuberose, Mexican shell flower, and rain lily all fit the bill.

3. Compost in the Cold

Compost all the trimmings from your garden. Even in the cool months, bacteria and fungi will be doing their magic to produce beautiful planting amendments for spring. Use one of the patented composting bins, build your own, or just layer the materials in a corner of the garden. If you are ambitious, turn the pile once or twice (a good way to monitor the moisture level) or simply leave as is.

Mulch and water your favorite trees and shrubs. Much editing is going on because of the drought, but these are ways to nurse these larger shrubs along.

4. Gifts for the Wildlife

Don’t forget the birds and beasts, too. A shallow bowl of water will give them a welcome drink and a cleansing splash. Place the bowl in a quiet place where visitors have a view of the surroundings and potential threats. Keep filled and flushed with clean water as needed.